NK/Z61, NK/Z64, NK/Z961, NK/Z964, NK/Z561, NK/Z564, NK/Z461, NK/Z464DK/Z61, DK/Z64, DK/Z961, DK/Z964, DK/Z561, DK/Z564, DK/Z461, DK/Z464 (W, H, Y) - PN25, 40, 64, 100 welded vacuum isolation gate valves are suitable for working temperatures ≤ 540C, working media for water, steam, and gas pipelines as opening and closing devices, especially suitable for steam turbines in thermal power plants. Vacuum condensation and vacuum negative pressure system, Play a vacuum isolation and sealing role. 5. Equipped with parallel double sealing and semi forced bidirectional sealing, the sealing surface has low friction and movement, and is easy to open and close. In addition, the sealing surface has a self compensation function for wear; The valve cover packing chamber is equipped with a sealing structure, which has a self expanding and tightening effect. High strength materials are used to seal all sides of the joint, making it easy for the system to be completely isolated from the atmosphere and having good system airtightness.